Where plains form on earth. Plains - what are they? Definition, description and difference between plains and mountains. The largest plains on Earth

Plain- this is an area of ​​land or seabed that has a slight fluctuation in heights (up to 200 m) and a slight slope (up to 5º). They are found at different altitudes, including at the bottom of the oceans. A distinctive feature of the plains is a clear, open horizon line, straight or wavy, depending on the surface topography. Another feature is that the plains are the main territories inhabited by people.

Since the plains occupy a vast territory, almost all natural zones exist on them. For example, the East European Plain includes tundra, taiga, mixed and deciduous forests, steppes and semi-deserts. Most of the Amazonian lowland is occupied by selvas, and on the plains of Australia there are semi-deserts and savannas.

Types of plains

In geography, plains are divided according to several criteria.

1. By absolute height they distinguish:

low-lying. The height above sea level does not exceed 200m. A striking example is the West Siberian Plain.

Exalted- with a height difference from 200 to 500 m above sea level. For example, the Central Russian Plain.

Nagornye plains whose level is measured at elevations of over 500 m. For example, the Iranian Plateau.

depressions- the highest point is below sea level. Example - Caspian lowland.

Separately allocate underwater plains, which include the bottom of basins, shelves and abyssal areas.

2 . By origin, plains are :

Accumulative (sea, river and continental) - formed as a result of the influence of rivers, ebbs and flows. Their surface is covered with alluvial sediments, and in the sea - with marine, river and glacial sediments. Of the sea, we can cite the West Siberian Lowland as an example, and of the river, the Amazon. Among continental plains, marginal lowlands that have a slight slope towards the sea are classified as accumulative plains.

Abrasion- are formed as a result of the impact of surf on land. In areas where strong winds prevail, rough seas are frequent, and the coastline is formed of weak rocks, this type of plain is more often formed.

Structural- the most complex in origin. In place of such plains, mountains once rose. As a result of volcanic activity and earthquakes, the mountains were destroyed. The magma flowing from cracks and splits bound the surface of the land like armor, hiding all the unevenness of the relief.

Ozernye- formed on the site of dry lakes. Such plains are usually small in area and are often bordered by coastal ramparts and ledges. An example of a lake plain is Jalanash and Kegen in Kazakhstan.

3. Based on the type of relief, plains are distinguished:

flat or horizontal– Great Chinese and West Siberian Plains.

wavy- are formed under the influence of water and water-glacial flows. For example, the Central Russian Upland

hilly- the relief contains individual hills, hills, and ravines. Example - East European Plain.

stepped- are formed under the influence of the internal forces of the Earth. Example - Central Siberian Plateau

concave- These include the plains of intermountain depressions. For example, the Tsaidam Basin.

Also distinguished ridged and ridged plains. But in nature it is most often found mixed type. For example, the Pribelsky ridge-undulating plain in Bashkortostan.

The land surface was repeatedly subjected to continental glaciation.
During the era of maximum glaciation, glaciers covered more than 30% of the land area. The main centers of glaciation in Eurasia were on the Scandinavian Peninsula, Novaya Zemlya, the Urals and Taimyr. In North America, the centers of glaciation were the Cordillera, Labrador, and the area west of Hudson Bay (Keewatin Center).
In the relief of the plains the traces of the last glaciation (which ended 10 thousand years ago) are most clearly expressed: Valdaisky- on the Russian Plain, Wurmsky- in the Alps, Wisconsin- in North America. The moving glacier changed the topography of the underlying surface. The degree of its impact was different and depended on the rocks that made up the surface, on its topography, and on the thickness of the glacier. The glacier smoothed out the surface, composed of soft rocks, destroying sharp protrusions. He destroyed fissured rocks, breaking off and carrying away pieces of them. Freezing into the moving glacier from below, these pieces contributed to the destruction of the surface.

Encountering hills composed of hard rocks along the way, the glacier polished (sometimes to a mirror shine) the slope facing its movement. Frozen pieces of hard rock left scars, scratches, and created complex glacial shading. The direction of glacier scars can be used to judge the direction of glacier movement. On the opposite slope, the glacier broke out pieces of rock, destroying the slope. As a result, the hills acquired a characteristic streamlined shape "mutton foreheads". Their length varies from several meters to several hundred meters, the height reaches 50 m. Clusters of “ram’s foreheads” form a relief of curly rocks, well expressed, for example, in Karelia, on the Kola Peninsula, in the Caucasus, on the Taimyr Peninsula, and also in Canada and Scotland.
At the edge of the melting glacier it was deposited moraine. If the end of the glacier, due to melting, was delayed at a certain boundary, and the glacier continued to supply sediments, ridges and numerous hills arose terminal moraines. Moraine ridges on the plain often formed near protrusions of subglacial bedrock relief. Ridges of terminal moraines reach a length of hundreds of kilometers at a height of up to 70 m. When advancing, the glacier moves in front of itself the terminal moraine and loose sediments deposited by it, creating pressure moraine- wide asymmetrical ridges (steep slope facing the glacier). Many scientists believe that most terminal moraine ridges were created by glacier pressure.
When a glacier body melts, the moraine contained in it is projected onto the underlying surface, greatly softening its unevenness and creating a relief main moraine. This relief, which is a flat or hilly plain with swamps and lakes, is characteristic of areas of ancient continental glaciation.
In the area of ​​the main moraine you can see drumlins- oblong hills, elongated in the direction of glacier movement. The slope facing the moving glacier is steep. The length of drumlins ranges from 400 to 1000 m, width - from 150 to 200 m, height - from 10 to 40 m. On the territory of Russia, drumlins exist in Estonia, on the Kola Peninsula, in Karelia and in some other places. They are also found in Ireland and North America.
The flow of water that occurs as the glacier melts washes away and carries away mineral particles, depositing them where the flow rate slows down. When meltwater deposits accumulate, thick layers of loose sediment, differing from moraine in the sorting of the material. Landforms created by meltwater flows as a result of erosion, and as a result of sediment accumulation, are very diverse.
Ancient drainage valleys melted glacial waters - wide (from 3 to 25 km) hollows stretching along the edge of the glacier and crossing pre-glacial river valleys and their watersheds. Deposits from glacial waters filled these depressions. Modern rivers partially use them and often flow in disproportionately wide valleys.
Kama- rounded or oblong hills with flat tops and gentle slopes, externally resembling moraine hills. Their height is 6-12 m (rarely up to 30 m). The depressions between the hills are occupied by swamps and lakes. Kames are located near the glacier boundary, on its inner side, and usually form groups, creating a characteristic kame relief.
Kamas, unlike moraine hills, are composed of roughly sorted material. The diverse composition of these sediments and the thin clays found especially among them suggest that they accumulated in small lakes that arose on the surface of the glacier. Ozy- ridges resembling railway embankments. The length of the eskers is measured in tens of kilometers (30-40 km), the width is in tens (less often hundreds) of meters, the height is very different: from 5 to 60 m. The slopes are usually symmetrical and steep (up to 40°).
The eskers extend regardless of the modern terrain, often crossing river valleys, lakes, and watersheds. Sometimes they branch, forming systems of ridges that can be divided into separate hills. The eskers are composed of diagonally layered and, less commonly, horizontally layered deposits: sand, gravel, and pebbles.
The origin of eskers can be explained by the accumulation of sediments carried by meltwater flows in their channels, as well as in cracks inside the glacier. When the glacier melted, these deposits were projected onto the surface. Zandra- spaces adjacent to terminal moraines, covered with deposition of meltwater (washed out moraine). At the end of the valley glaciers, the outwash is insignificant in area, composed of medium-sized rubble and poorly rounded pebbles. At the edge of the ice cover on the plain, they occupy large spaces, forming a wide strip of outwash plains. Outwash plains are composed of extensive flat alluvial fans of subglacial flows, merging and partially overlapping each other. Landforms created by the wind often appear on the surface of outwash plains.
An example of outwash plains can be the strip of “woodland” on the Russian Plain (Pripyatskaya, Meshcherskaya).
In areas that have experienced glaciation, there is a certain regularity in the distribution of relief, its zoning In the central part of the glaciation region (Baltic Shield, Canadian Shield), where the glacier arose earlier, persisted longer, had the greatest thickness and speed of movement, an erosive glacial relief was formed. The glacier carried away pre-glacial loose sediments and had a destructive effect on bedrock (crystalline) rocks, the degree of which depended on the nature of the rocks and the pre-glacial relief. The cover of a thin moraine, which lay on the surface during the retreat of the glacier, did not obscure the features of its relief, but only softened them. The accumulation of moraine in deep depressions reaches 150-200 m, while in neighboring areas with bedrock ledges there is no moraine.
In the peripheral part of the glaciation area, the glacier existed for a shorter time, had less power and slower movement. The latter is explained by a decrease in pressure with distance from the glacier's feeding center and its overload with debris. In this part, the glacier was mainly unloaded from debris and created accumulative relief forms. Beyond the boundary of the glacier, directly adjacent to it, there is a zone whose relief features are associated with the erosion and accumulative activity of melted glacial waters. The formation of the relief of this zone was also affected by the cooling effect of the glacier.
As a result of repeated glaciation and the spread of the ice sheet in different glacial epochs, as well as as a result of movements of the edge of the glacier, forms of glacial relief of different origins turned out to be superimposed on each other and greatly changed. The glacial relief of the surface freed from the glacier was exposed to other exogenous factors. The earlier the glaciation, the more, naturally, the processes of erosion and denudation changed the relief. At the southern boundary of maximum glaciation, the morphological features of the glacial relief are absent or very poorly preserved. Evidence of glaciation are boulders brought by the glacier and locally preserved remains of heavily altered glacial deposits. The topography of these areas is typically erosive. The river network is well formed, the rivers flow in wide valleys and have a developed longitudinal profile. To the north of the boundary of the last glaciation, the glacial relief has retained its features and is a disorderly accumulation of hills, ridges, and closed basins, often occupied by shallow lakes. Moraine lakes fill up relatively quickly with sediment, and rivers often drain them. The formation of a river system due to lakes “strung” by the river is typical for areas with glacial topography. Where the glacier persisted the longest, the glacial topography was changed relatively little. These areas are characterized by a river network that has not yet been fully formed, an undeveloped river profile, and lakes that have not been drained by the rivers.

Plain

Plain

relatively flat surface with small (up to 300–400 m) fluctuations in heights and a predominance of small (up to 5–10°) slopes; one of the two main types of relief on the globe (the second is mountains). Plains occur at different abs. altitudes on land and at the bottom of oceans and seas (underwater plains). On land there are plains: lowlands, or lowlands located below the sea level. m. (for example, the Caspian lowland), low - at high. up to 200 m, elevated – 200–500 m, mountainous (plateaus, plateaus), sloping piedmont. The most typical plains are platforms and intermountain depressions. They are characterized by an open horizon line - smooth or wavy, with soft outlines. According to the features of the relief, flat, wavy, ridged, hilly, ridged, stepped (terraced) plains are distinguished. Based on the origin and predominance of certain exogenous processes, structural (for example, plateaus), denudation and accumulative plains are distinguished. Most of the large plains (Russian, West Siberian, Central Siberian, North American, Amazonian) have a complex origin. Plains occupy more than 20% of the land and are the main... territories of human settlement. At the bottom of seas and oceans, they are divided depending on the depth, origin, and type of bottom organisms (abyssal, bathyal plains).

Geography. Modern illustrated encyclopedia. - M.: Rosman. Edited by prof. A. P. Gorkina. 2006 .

See what “plain” is in other dictionaries:

Cm … Synonym dictionary

PLAIN, plains, women. The earth's surface without mountains or significant hills. “The mountains are gone; a plain began without end.” Nekrasov. “And that’s all, echoing the plain, a cheer rang out in the distance.” Pushkin. Ushakov's explanatory dictionary. D.N. Ushakov. 1935 1940 ... Ushakov's Explanatory Dictionary

PLAIN, a large area of ​​the Earth's surface over which there are no significant fluctuations in elevation. Some plains, such as the PENEPLANE, are the result of the destruction of higher ground. But most of the plains... ... Scientific and technical encyclopedic dictionary

PLAIN, s, female. A flat surface of the earth, without high hills, as well as (special) a section of the bottom of the sea or ocean without sharp fluctuations in heights. Russian plains. | adj. flat, oh, oh. R. landscape. Ozhegov's explanatory dictionary. S.I. Ozhegov, N.Yu. Shvedova... ... Ozhegov's Explanatory Dictionary

- [German] Flache, Ebenes Land; French plaine pays] surface, usually significant in area, but with slight fluctuations in height; if the latter reach several hundred m (W. Siberia up to 200 m), then over a long distance, so the heights ... ... Geological encyclopedia

plain- About the size, nature of the surface, color. Boundless, boundless, endless, boundless, boundless, brown, wavy, scorched, faded, smooth, blue, bluish-brown, huge, yellow, green, golden, boundless,... ... Dictionary of epithets

plain- — EN plain An extensive, broad tract of level or rolling, almost treeless land with a shrubby vegetation, usually at a low elevation. (Source: MGH)… … Technical Translator's Guide

plain- Relatively flat surfaces, sometimes quite extensive, with slight variations in height and small slopes... Dictionary of Geography

- (Deut.1:1, Deut.2:8). Palestine is a mountainous land, and therefore there are few wide plains. The most notable of them are the following: a) the plain of Jezreel, or Ezdrilon. b) a plain running along the Mediterranean Sea from the city of Carmel to the stream of Egypt, c)… … Bible. Old and New Testaments. Synodal translation. Biblical encyclopedia arch. Nikifor.

Noun, g., used. compare often Morphology: (no) what? plains, why? plain, (see) what? plain, what? plain, about what? about the plain; pl. What? plains, (no) what? plains, why? plains, (see) what? plains, what? plains, about what? about the plains... ... Dmitriev's Explanatory Dictionary

Ararat Plain in Armenia Plains are areas of the land surface, the bottom of seas and oceans, which are characterized by: slight fluctuations in heights (up to 200 m) and a slight slope of the terrain (up to 5°). Plains occupy 64% of the land area.... ... Wikipedia

Books

• Russian plain. Experience of spiritual resistance. This collection includes materials from the international scientific and practical conference “Russian Plain. Experience of Spiritual Resistance”, held in January-February 2013 on the initiative of…

It is characterized by a predominantly flat landscape, prevailing over the mountainous one not only on land, but also under water.

What are plains?

Plains are relatively flat, vast areas in which the heights of neighboring areas fluctuate within 200 m; they have a slight slope (no more than 5 m). The most illustrative example of a classical plain is the West Siberian Lowland: it has an exclusively flat surface, the height difference on which is almost imperceptible.

Relief features

As we have already understood from the above definition, plains are areas with flat and almost flat terrain, without noticeable ascents and descents, or hilly, with a smooth alternation of increases and decreases in the surface.

Flat plains are generally insignificant in size. They are located near seas and large rivers. Hilly plains with uneven terrain are more common. For example, the relief of the East European (Russian) Plain is characterized by the presence of both hills more than 300 meters high and depressions whose height is below sea level (Caspian Lowland). Other famous plains of the world are the Amazon and Mississippi. They have a similar topography.

Features of the Plains

A distinctive feature of all plains is a clearly defined, clearly visible horizon line, which can be straight or wavy, which is determined by the topography of a particular area.

Since ancient times, people have preferred to create settlements on the plains. Since these places are rich in forests and fertile soil. Therefore, today the areas of the plains are still the most densely populated. Most of the minerals are mined on the plains.

Considering that the plains are areas with a huge area and great extent, they are characterized by a variety of natural zones. Thus, on the East European Plain there are territories with mixed and broad-leaved forests, tundra and taiga, steppe and semi-desert. The plains of Australia are represented by savannas, and the Amazonian lowlands are represented by selvas.

Climatic features

Plain climate is a fairly broad concept, as it is determined by many factors. These are geographical location, climate zone, area of ​​the region, length, relative proximity to the ocean. In general, the flat terrain is characterized by a clear change of seasons, due to the movement of cyclones. Often on their territory there is an abundance of rivers and lakes, which also affect climatic conditions. Some plains have their huge area consisting of continuous desert (Western Plateau of Australia).

Plains and mountains: what is their difference

Unlike plains, mountains are areas of land that rise sharply above the surrounding surface. They are characterized by significant fluctuations in elevation and large terrain slopes. But small areas of flat terrain are also found in the mountains, between mountain ranges. They are called intermountain basins.

Plains and mountains are landforms whose differences are based on their origin. Most mountains were formed under the influence of tectonic processes, the movement of layers occurring deep in the earth's crust. In turn, the plains lie predominantly on platforms - stable areas of the earth's crust; they were influenced by external forces of the Earth.

Among the differences between mountains and plains, in addition to appearance and origin, we can highlight:

• maximum height (near the plains it reaches 500 m, near the mountains - over 8 km);
• area (the area of ​​mountains on the entire surface of the Earth is significantly inferior to the area of ​​plains);
• the likelihood of earthquakes (on the plains it is almost zero);
• degree of mastery;
• ways of human use.

Largest plains

Located in South America, it is the largest in the world, its area is about 5.2 million square meters. km. It has a low population density. It is characterized by a hot and humid climate, dense tropical forests covering vast areas and teeming with animals, birds, insects and amphibians. Many species of the animal world of the Amazonian lowlands are not found anywhere else.

The East European (Russian) Plain is located in the eastern part of Europe, its area is 3.9 million square meters. km. Most of the plain's territories are located in Russia. It has a gently flat terrain. The bulk of large cities are located here, and a significant share of the country’s natural resources is concentrated here.

Located in Eastern Siberia. Its area is about 3.5 million square meters. km. The peculiarity of the plateau is the alternation of mountain ridges and wide plateaus, as well as frequent permafrost, the depth of which reaches 1.5 km. The climate is sharply continental; the vegetation is dominated by deciduous forests. The plain is rich in mineral resources and has an extensive river basin.

My friend Nina lives in Kazakhstan. When I went to visit her, I saw what the plains of this country are like. We drove by car to the village along the spring steppe, and it seemed to me that it had no boundaries.

What are called plains

Today my son Sasha and I are learning geography again. Let's figure out what plains are and what their characteristics are.

Plains are large areas of the earth's surface with a slight slope (no more than 5°). Height fluctuation on the plain is up to approximately 200 m.

Signs of plains by absolute height.

1. Elevated (elevation difference 200–500 m above sea level).
2. Low-lying (elevation difference no more than 200 m).
3. Mountainous (lie at a level above 500 m).
4. Depressions (their highest point is located below sea level).
5. Underwater plains.

The plains differ in the type of relief:

• horizontal or flat;
• wavy;
• hilly;
• stepped;
• concave.

There are denudation and accumulation plains. Denudation appeared during the destruction of mountains. Accumulative ones are formed during the accumulation of sedimentary deposits.

The largest plain on Earth

To make it clear to Sasha what plains are, we looked at the Amazonian lowland as an example. This plain is the largest on our planet. Its area is more than 5 million km². It is located in South America, in the Amazon River basin and was formed as a result of the activity of this river; it is accumulative. The plain stretches from the Andes to the Atlantic Ocean. The relief of this area is heterogeneous. Western Amazonia is very low and flat. In the eastern Amazon you can find elevations up to 350 m. But basically this plain is flat.

Economic importance of the plains

I told my son how important the plains are to the economy. The plains have always been of great importance in people's lives. Grain and vegetable crops grow best in their spaces.

Cows, sheep and horses graze in the vast expanses of steppes, pampas and prairies. This is possible thanks to the grasses and shrubs that grow in abundance on the plains.

The plains provide the basis for people's nutrition, and this is very important.

Mostly villages and large cities with their industry are located on the plains.

Plains are the most convenient places for people and animals to live. The plains are home to the majority of people, 65% of the world's population.

Plains and mountains are the main forms of the earth's surface. They were formed as a result of geological processes that have shaped the face of the Earth throughout geological history. Plains are vast spaces with calm, flat or hilly terrain and relatively small fluctuations in relative heights (no more than 200 m).

Plains are divided by absolute height. Plains with an absolute height of no more than 200 m are called lowlands, or lowlands (). Plains, which range from 200 to 500 m, are called elevated, or uplands (East European, or Russian). Plains whose height is over 500 m above sea level are called high or plateaus (Central Siberian).

Due to their considerable height, plateaus and hills usually have a more dissected surface and rugged terrain compared to lowlands. Elevated plains with flat surfaces are called plateaus.

The largest lowlands: Mississippian, Indo-Gangetic, German-Polish. represents an alternation of lowlands (Dnieper, Black Sea, Caspian, etc.) and uplands (Valdai, Central Russian, Volyn-Podolsk, Volga, etc.). Plateaus are most widespread in Asia (Central Siberian, Deccan, etc.), in (East African, South African, etc.), in (West Australian).

The plains are also divided by origin. The majority (64%) of the plains formed on platforms; They are composed of layers of sedimentary cover. Such plains are called stratal or platform plains. The Caspian lowland is the youngest plain, and is an ancient platform plain, its surface has been significantly modified by flowing waters and other external processes.

The plains that arose as a result of the removal of products of mountain destruction (denudation) from the destroyed base of the mountains (basement) are called denudation, or base, plains. Mountain destruction and transport usually occurs under the influence of water, ice and gravity. Gradually, the mountainous country smoothes out, levels out, turning into a hilly plain. Denudation plains are usually composed of hard rocks (small hills).

The main lowlands and plateaus of the world